DE3719526A1 - METHOD FOR CONTINUOUSLY PRESERVING PIECE OF FOODSTUFFS AND DEVICE FOR ITS IMPLEMENTATION - Google Patents

Abstract

Method and apparatus for the continuous preservation of lumpy product in which the lumpy product is blanched, pasteurised or sterilised and then packaged hot or cooled, under aseptic conditions. In order to treat the lumpy product, e.g. chunks of fruit, in the gentlest possible manner, the heat treated product is continuously passed, without using pressure, to a drum (4) having a conveyor (2) therein through which a pasteurised liquid (10) is continuously circulated, the liquid (10) also being fed to the drum separate from the product under aseptic conditions, and having its level inside the drum maintained at a constant pre-selected value with excess liquid (10) being drawn off and re-sterilised for return to the drum (4), and the lumpy product inside the drum being continuously separated from the liquid by movement of the product through the drum by the conveyor (2), which is preferably in the form of a sieve insert with internal spiral rotatable within the drum (4) which is inclined.

Description

The invention relates to a method for continuous Chen preservation of chunky food, in which the lumpy or lumpy good to be treated blanched, heat-treated and hot or under asepti conditions are cooled and filled, and a device for performing this method a blanching and pasteurization device and min least another device for thermal loading act of lumpy food.

From DE-PS 28 29 381 is a discontinuous Ver drive to sterilize chunky food, especially of vegetables, meat and ready meals, known in which a batch of to be sterilized Guts in a rotating drivable wobble  direct introduction of prestressed steam into the vessel is heated, allowing the steam in the vessel sieren and the solid components after the Steri sterilize from the vessel under sterile conditions pulls. To now on the one hand the fixed components of the sterilizing foods as gently as possible act and protect against mechanical damage and on the other hand the heat transfer through the lumpy, accelerate solid components, what from biologi human and nutritional reasons (protection of Vitamins, flavors and other essential ingredients parts before thermal destruction) is desirable, is working discontinuously in this known Process that initially supplied to the lumpy good Amount of liquid called "lubricant" (Juice, water, roast stock, sauce or the like) against above the total liquid required for lubrication kept small while the main part of the Only add liquid at a later time on which the solid components as a result of the heating tongue begin to soften.

Like all discontinuous processes, this one too Process the disadvantage that the throughput to behan delndem good by the necessary "set-up times" is limited in which the swashplate is loaded and unloaded in which the good until reaching Sterilisa tion temperature heated and then abge is cooled and in which the contained in the wobble air and acid to the extent necessary must be made free of substances. But above all, dis continuous sterilization procedures always the night partly because of the opening and closing in paragraphs of the sterilization vessel is a continuously aseptic one Management of the overall process is not possible.  

From DE-OS 29 52 544 is a continuous Ver drive to pasteurize, i.e. to heat treatment a temperature of maximum 90 to 100 ° C, from piece gene food and a device for implementation tion of this method known. This will be Acting lumpy goods a "scratch heater", d. H. an inclined screw tube, in which there is a screw conveyor that removes the material from the tie The end of the entry for the higher discharge end continuously funding, being in the funding path Steam inlets are built through which steam into the Auger tube is introduced.

Separated from the pasteurization of lumpy life means in the screw tube, is with the lumpy Liquid to be mixed well to a desired temperature heated and in the area of the discharge end in the Auger tube introduced in this area as Mixing chamber is formed.

This known continuous process is for the Heat treatment of particularly delicate lumpy Foods, e.g. peaches, pears, Pineapple and the like, not suitable because the Rela tiv movement between the rotating screw conveyor and the inner surface of the screw tube to considerable Rei exercise and squeezing the funded goods and thus leads to its mechanical damage. Beyond that cause the pressure conditions within the individual NEN screw flights of the screw conveyor that the Stücki parts are pressed firmly against each other, which Excellent heat transfer through the individual pieces difficult and, above all, inhomogeneous. Depending on where the individual pieces come to be individual portions of the goods to be treated by and through to the desired pasteurization temperature  has been heated, while other shares with the same ver are superficially pasteurized while the number of germs inside the affected pieces high due to the lack of sufficient heat transfer is. For cooling under aseptic conditions, this is known methods are neither determined nor suitable.

Finally, from US-PS 41 81 072 is a continuous method for sterilizing lumpy life means and a device suitable for this purpose are known, where the lumpy good through a pressure-tight task sluice in a horizontally arranged, tubular Autoclave is continuously entered. The place fixed, i.e. non-rotating autoclave is complete filled with a cooking liquid (sauce), and the one Carrying the lumpy food is dosed so that the solid components in the form of discrete particles in of the liquid are "dispersed". One in the car the conveyor screw located in the slave moves the liquid with the solid particles distributed in it from the one end of contract to end of discharge, at which in turn a print tight outlet lock for the heat-treated material is seen. The content of the autoclave is with the help biased, superheated steam under constant Overpressure maintained. The liquid (sauce) is in the Circuit continuously withdrawn from the autoclave, separated from the lumpy good in a well-known white sterilized and with a temperature of over 100 ° C returned to the autoclave.

Because of the relative movement between the screw conveyor and stationary autoclave there is also a risk here mechanical damage to the solid, lumpy Parts through friction and crushing. Another after part of the known method is that  Degree of distribution of the solid components in the liquid a crucial role in terms of effectiveness speed of the process plays, so the ratio between lumpy goods and used as a heat transfer medium th liquid regardless of the material to be treated table must be kept constant, so not in wide Limits selectable and adjustable to different goods is.

The invention is based, a continuum Process and a suitable device to improve the genus mentioned at the beginning so that the goods to be treated in a particularly gentle manner, with the greatest possible avoidance of mechanical damage, but also avoiding thermal damage essential ingredients of food, pasteuri is sterilized or sterilized and cooled. Procedure and The device should in particular be designed that so be the continuous heat treatment particularly delicate lumpy food allows is, so far only in the already packaged state, for. B. in cans or jars, could be sterilized; here it is particularly sensitive fruit and vegetables such as peaches, pears, pineapples, tomatoes pieces, beans, mushrooms, but also for pasta like at for example ravioli or the like.

This task is ge in a process of the beginning called genus solved according to the invention in that the lumpy good pasteurized during blanching the pasteurized material is inclined without pressure orderly drum is fed that a liquid separate from the fixed proportions of food continuously pasteurized or sterilized and under aseptic conditions also fed to the drum the liquid level inside the drum  kept at an adjustable value, surplus removed liquid and the lumpy good still within the drum continuously from the liquid speed is separated.

In a device of the type mentioned in the introduction the object is achieved in that the further facility for the thermal treatment of the chunky food an inclined drum is within which a motor-driven sieve set is arranged, which on its inner lateral surface che a snail gear firmly connected to the jacket carries, which has sieve-like openings.

The treatment of the lumpy good takes place after it The method according to the invention is particularly gentle, namely both mechanically and thermally Terms, but at the same time a good and quick Heat transfer and thus a safe germ killing he aims to be. In contrast to the known methods can be particularly gentle on large pieces according to the invention be treated.

For lumpy foods of the type in question it was always a special problem in the finished end product a constant relationship between pieces to achieve strong, solid parts and liquid. Because this is based on the known methods on continuous che way was not possible, you have discontinuous worked and each batch before filling the product tes individually to the desired or required Ratio between solid and liquid proportions posed. With the invention, the professional world is in contrast via a continuous process to the Hand given with which it is possible in the finished end product a constant relationship between fixed  and to obtain liquid portions of the food, in both hot and cold filling of the final product.

The unpressurized feeding of the blanched and pasteuri good means first of all exclusion of pipes and pumps and thus already in this early stage of the overall process a particularly scho treatment of the lumpy good.

The use of an inclined drum, which, separate from the lumpy good, under aseptic conditions liquid is supplied, which within the Drum kept constant at a selectable level means that the blanched and pasteurized A aseptic tank, which represents the drum, is fed. A thermi takes place in this aseptic tank treatment of the goods instead, under "thermal Treatment "both heating and cooling is to be understood. So when the food is hot to be filled, it is separated from the lumpy Well pasteurized or sterilized liquid hot introduced into the drum designed as an aseptic tank. In contrast, is a cold filling of the lumpy life with intended, the pasteurized or ste previously sterilized liquid under aseptic conditions cooled and inserted cold into the drum.

The inclined position of the drum also causes its in only partially, preferably less than that Accounts for half of their volume, with lumpy goods and Liquid is filled. In the drum a sta maintain a state where one is minimal possible amount of ballast by the most energy consuming Treatment stage of the overall process is carried along, but at the same time for optimal heat transfer  catered for by the chunky portions of the food because there are always new areas of the lumpy good with of the rivers used as a heat transfer medium or cooling medium liquid come into contact, but at the same time optimum protection against mechanical stress is achieved.

An important feature of the method according to the invention is that the lumpy good still within the Drum continuously separated from the liquid becomes. That means that the lumpy good mind Mostly in a drained state, i.e. practically without rivers portion of liquid that leaves the drum and then either another thermal treatment that a Pasteu rization, sterilization or cooling can be without unnecessary ballast can be added or under aseptic conditions in suitable containers fills and if necessary continuously in the desired Relationship with the separated from the lumpy good in a circle run guided and separately pasteurized or sterilized, possibly already cooled liquid can be moved. In this way, it is the same permanent relationship between solid and liquid Share of the food in the finished end product continuous process management on particularly simple achievable in a manner and under aseptic conditions.

To separate the lumpy good from the liquid is preferably a rotating inside the drum, motor-driven sieve insert used. This Sieve insert can be a sieve drum, but also one Kind of cage made of spaced bars ben, provided the distance between the bars is so is small that the lumpy good does not fall through can.  

The sieve insert used bears on his inner man surface firmly connected to the jacket kengang, which, like the sieve insert itself, is sieve-like Can have openings.

The sieve insert arranged inside the drum has usually a diameter of about 60 to 100 cm and a length of about 1.5 to 3 m and turns very long inside the fixed outer drum sam, namely at a speed of about 1 to 10 rpm.

Due to the inclined position of the drum and thus the in its rotating sieve insert now moves the lumpy Well slow through the turns of the inside Shell surface of the sieve insert ganges from the lower end of the entry to the higher one the discharge end of the drum.

Because the filling with lumpy good and liquid only fills a small part of the interior of the drum, there are still two to three screw turns or the upper one Part of the sieve insert available its passage through the liquid from the lumpy good drain and through the holes in the sieve insert or through the opening located between the bars can flow out. In this way it gets there lumpy good in drained condition in the handover or outlet lock, while in the previously known Process the liquid portion of the discharge about 20 made up up to 40 wt .-%.

Preferably as a liquid, that of as aseptic tank trained drum is fed and the, depending after the procedure, as a heat transfer medium or cooling medium is used, one with the lumpy to be treated  Well used isodense liquid. This will make him is enough that the lumpy solid portions in the liquid Float freely, so neither sink to the ground nor up floating on the surface. In this way it becomes piece Handle the goods particularly gently within the drum delt.

Instead of an isodense liquid, one with the juice contained in the chunky food iso tonic liquid can be used so that not only the advantages brought about by the same density targets, but also osmotic processes be prevented.

Another preferred embodiment of the Invention according to the method is that steam or inert gas introduced into the drum and the drum under egg slightly positive pressure is maintained. The easy one positive pressure serves to prevent air or air from entering Oxygen and therefore germs in the as aseptic tank to prevent trained drum. On the other hand, can but also the treatment in the drum under vacuum or reduced pressure or under overpressure and use Rotary lock valves are made when this is off should be desired or appropriate for certain reasons te. However, the method according to the invention is usually used under normal pressure or to maintain aseptic Conditions under the slightly positive pressure mentioned be performed.

In a further advantageous embodiment of the method according to the invention is the blanched and pasteurized lumpy good before entering the Vented from the drum and thereby from cellular air and  released oxygen.

As already mentioned, it is pulled out of the drum ne, separated from the lumpy liquid in the Cycle and after repeated pasteurization or Sterilization again under aseptic conditions Drum fed. Instead of a liquid circuit fes can also separate circuits of different rivers be applied so that for treatment in the drum z. B. water, a brine or a Syrup can be used while in the drum separated lumpy good when filling a sauce or a juice can be added. This is also possible speed represents a significant advantage of the invention procedure with regard to its almost univer represent usability.

The piece goods in the drum can be sprayed with the pa-controlled or sterilized liquid supplied under aseptic conditions, or the piece goods and the liquid can be passed through the drum in countercurrent. Spraying the lumpy good in the drum is preferred because the heating or cooling of the lumpy good - depending on whether working with hot or cooled liquid - takes place in a particularly effective manner.

According to the invention, ge is preferably used in the acidic range works because there are pathogenic germs in this area can not multiply, while on the other hand mold and yeast already during pasteurization in the blan chier station are destroyed. That is why the rivers liquid preferably adjusted to pH ≦ 4.5. The one adjustment of the pH can be done in a manner known per se with the help of physiological and food law  harmless acids. Ascorbic acid, lemons Acid, sulphurous acid and acid phosphates are here for particularly suitable agents, as they are also serve as antioxidants and browning reactions prevent.

If the method according to the invention is not for pasteurization and cold aseptic filling of the food to be treated, but z. B. should also be used for sterilization, which is usually carried out at temperatures between about 100 and 140 ° C and / or under increased pressure of up to 5 × 10 ⁵ Pa, then the lumpy material is preferably successively by several of the drums described continuously passed through and subjected to different thermal treatments. In this embodiment of the method according to the invention, a first drum can be designed as a control station, a further drum as a sterilization station and a third drum can finally be designed as a cooling station. The method according to the invention can also be combined with known methods and known devices, but care must be taken to ensure that the advantages achieved according to the invention are not compensated for by the disadvantages of the known methods and devices or are even compensated for.

The invention is based on the drawing ago explained, some of which is a flow chart of the inventions method according to the invention and partly a schematic Representation of the device according to the invention.

The lumpy or previously lumped food L to be treated is continuously introduced into the blanching and pasteurization station 1 with the aid of known, not shown funding. The blanching and pasteurizing is carried out in a known manner, preferably using steam. The blanched and pasteurized chunky goods arrive without pressure, e.g. B. on a slide, in the sieve insert 2 , which is motor-driven, rotates within the drum 4 about the axis A.

Sterilized liquid is removed from a storage container 3 , which is connected to a conventional sterilizer S , cooled in a cooler 13 and continuously introduced into the drum 4 under lines 14 and 15 under aseptic conditions. The drum 4 and the sieve insert 2 , which is designed as a sieve drum in the illustrated embodiment, are filled to the level 20 with the liquid 10 , which contains particles of the lumpy material 11 . The liquid 10 used is isodense with the particles 11 of the lumpy good.

The sieve insert 2 , which rotates slowly about the axis A , carries on its inner lateral surface 21 a worm gear 22 which is firmly connected to the casing and which can likewise have perforations similar to sieves. The piece good 11 migrates in the liquid 10 , driven by the screw 22 , slowly from the lower entry end of the drum 4 to the higher discharge end. In the projecting above the liquid level 20 upper part of the worm gear 22 there is a continuous separation between the lumpy material 11 and the liquid 10 , which flows through the holes in the sieve insert 2 . On the remaining path to the end of the screw flight 22 , the liquid can drip off the solid parts of the lumpy material. Within half of the drum 4 , the dwell time of the lumpy material in the liquid can be adjusted to a desired value by varying the speed of the sieve insert 2 by changing the steepness of the worm gear 22 , but also by regulating the level 20 .

In this way, through the feed lock 5 in the lower part of the sieve insert 2 stüc kige good practically without any noticeable liquid part continuously through the transfer or outlet lock 7 in the upper part of the drum 4 who withdrawn from where it is under aseptic conditions either in another drum of basically the same type for further thermal treatment or in an aseptic filling station 17 . The drained lumpy good 11 can be discharged into the filling station 17 using known methods. The lumpy good can be filled without the addition of liquid or with the addition of liquid; in the latter case, sterilized liquid is continuously admixed via lines 14 and 16 , while maintaining a selectable but constant ratio of solid and liquid components of the food.

The inclination of the drum 4 and thus the Siebeinsat zes 2 is variably adjustable; it can be about 5 to 30 ° with respect to the horizontal.

The drum 4 can also be supplied with steam D or inert gas, which serve to maintain a slightly positive pressure inside the drum 4 in order to prevent the entry of atmospheric oxygen, germs, spores and the like.

Excess liquid 10 and possibly condensed steam are withdrawn through the outlet 6 from the drum 4 and fed via the line 12 to the storage container 3 , the level regulation being able to take place fully automatically using known regulating and control devices.

Claims (16)

1. A process for the continuous preservation of lumpy foods, in which the lumpy or lumped material to be treated is blanched, heat treated and hot or cooled and filled under aseptic conditions, characterized in that the lumpy material is pasteurized during blanching, the pasteurized material is fed without pressure to a drum arranged at an incline, such that a liquid is separately pasteurized or sterilized separately from the solid portions of the food and is also fed to the drum under aseptic conditions, the liquid level within the drum being kept constant at an adjustable value, excess liquid is drawn off and the lumpy material is continuously separated from the liquid inside the drum. 2. The method according to claim 1, characterized in that that as a liquid with the piece to be treated  Good isodense liquid is used. 3. The method according to claim 1 or 2, characterized records that as a liquid with the one in the piece Juices contain isotonic rivers liquid is used. 4. The method according to any one of claims 1 to 3, characterized characterized in that steam or inert gas into the drum introduced and the drum under a slightly positive Pressure is maintained. 5. The method according to any one of claims 1 to 3, characterized characterized in that the treatment in the drum under reduced pressure. 6. The method according to any one of claims 1 to 5, characterized characterized that the blanched and pasteurized Vent lumpy goods before entering the drum tet and thereby of cellular air and dissolved acid material is exempted. 7. The method according to any one of claims 1 to 6, characterized characterized in that the withdrawn from the drum by liquid separated from the lumpy material in the circuit performed and after renewed pasteurization or sterile again under aseptic drum conditions is fed. 8. The method according to any one of claims 1 to 7, characterized characterized in that the lumpy good with the under asep fed, pasteurized or sterilized liquid is sprayed in the drum. 9. The method according to any one of claims 1 to 8, there characterized in that to separate the lumpy  Guts of the liquid one inside the drum ro animal sieve insert is used. 10. The method according to any one of claims 1 to 9, there characterized in that the pH of the liquid is set to ≦ 4.5. 11. The method according to any one of claims 1 to 10, there characterized in that the lumpy good in the Trom heated or cooled under aseptic conditions and the liquid supplied to the drum is demented talking or heated is supplied. 12. The method according to any one of claims 1 to 11, there characterized in that the lumpy good one after the other continuously through several of the drums and different thermal treatments gene is subjected. 13. An apparatus for performing the method according to one of claims 1 to 12 with a blanching and pasteurization device and at least one further ren device for the thermal treatment of the pieces of food, characterized in that the further device for thermal treatment of the pieces of food a inclined drum ( 4 ), within which a motor-driven sieve set ( 2 ) is arranged, which carries on its inner lateral surface ( 21 ) a fixedly connected to the jacket worm gear ( 22 ). 14. The apparatus according to claim 13, characterized in that the sieve insert ( 2 ) is a sieve drum. 15. The apparatus of claim 13 or 14, characterized in that the inclination of the drum ( 4 ) is variably adjustable and is about 5 to 30 ° with respect to the horizontal. 16. Device according to one of claims 13 to 15, characterized in that the drum ( 4 ) in the region of its lower end, a feed lock ( 5 ) for the lumpy material to be treated and an outlet ( 6 ) for excess liquid to be drawn off, in the area their upper end a transfer or outlet lock ( 7 ) for the separated from the liquid good, an inlet for the separately pasteurized or sterilized aseptic liquid and an inlet for steam and possibly inert gas.